High-speed Local Area Networks Research Articles

Fuzzy MIMO model for efficient control of complex processes with uncertainties and nonlinearities

This paper shows the impact of the MIMO model on control system solutions for efficient control of complex nonlinear processes (multiple input, multiple output model) in terms of efficiency, product quality and energy efficiency. In modern automatic control systems, there is a need for increased capacity in long-distance data transmission, high-speed local area networks, etc. Capacity can be increased by extending the frequency range. However, the application of these techniques is limited by biosafety requirements, limited power supply (in mobile devices), and electromagnetic compatibility. Therefore, if these approaches to communication systems do not ensure the speed of transmission of information about technological processes, a weak correlation will appear. The values of indicators for the construction and use of fuzzy MIMO models of control decisions are expressed in the form of linguistic variables. The fuzzy MIMO model makes qualitative decisions in the control of complex processes. This includes uncertainty and nonlinearity problems, which are used to optimize complex systems.

BER PERFORMANCE ANALYSIS OF 4QAM/OFDM OVER DIFFERENT SCENARIOS OF LAPLACE FADING CHANNEL.

Multicarrier transmission, also known as (OFDM) Orthogonal Frequency Division multiplexing, in wireless communications, it has been proven to be an essential technique for countering multipath fading. It has been used successfully for HF radio applications and has been selected as the interface for digital audio transmission, digital terrestrial TV broadcasting, and high-speed wireless local area networks in Europe. In this paper, we suggested a new design for modeling multipath fading channels, such as the Laplace fading channel, in order to discover new simulation results and effects. Furthermore, the variance of the Laplace fading channel has been computed and the new Bit Error Rate (BER) derivation is established, and the performance of (M-QAM), M-ary Quadrature Amplitude Modulation (with M=4 over OFDM system under Laplace fading channels in Additive White Gaussian Noise (AWGN) is discussed and compared to the conventional M-QAM/OFDM system Rayleigh fading channel in AWGN. All the simulation results are examined using the optimum signal detection based on the Euclidean distance and evaluated using Monte-Carlo simulation.

High-Performance Computing (HPC) design to improve the quality of Introduction of Parallel Computing lectures

High-Performance Computing (HPC) has been created to improve the quality of Pengantar Komputasi Parallel lectures. HPC consists of two PCs with AMD Ryzen 7 processor connected by high-speed LAN. HPC is used to solve problems that students can’t practice Parallel Computing because the computer used is not adequate. So it takes a machine that can used together that has many processors, so the problems encountered are resolved. The results obtained, participants can use more than four processors to solve tree problems directly.

Uplink design in VLC systems with IR sources and beam steering

The need for high-speed local area networks to meet the recent developments in multimedia and video transmission applications has recently focused interest on visible light communication (VLC) systems. Although VLC systems provide lighting and communications simultaneously from light emitting diodes, LEDs, the uplink channel design in such a system is a challenging task. In this paper, we propose a solution in which the uplink challenge in indoor VLC is resolved by the use of an Infrared (IR) link. We introduce a novel fast adaptive beam steering IR system (FABS-IR) to improve the uplink performance at high data rates while providing security for applications. The goal of our proposed system is to enhance the received optical power signal, speed up the adaptation process and mitigate the channel delay spread when the system operates at a high transmission rate. The channel delay spread is minimised from 0.22 ns given by hybrid diffuse IR link to almost 0.07 ns. At 2.5 Gb/s, our results show that the imaging FABS-IR system accomplished about 11.7 dB signal to noise ratio (SNR) in the presence of multipath dispersion, receiver noise and transmitter mobility.

Low fire M-phase lithium based dielectric ceramics for microwave applications: A review (I)

ABSTRACTMicrowave dielectric ceramics have been used for various applications such as wireless communications including mobile communications, local-area networks, ultra high speed local area networks, intelligent transport systems, satellite communications and consumer electronic products. The continuous trend towards portable, light weight and multifunctional electronic components has motivated scientists to enhance the properties of existing materials and develop new dielectric materials. During the past 3 decades, a lot of research has been taken place in this field. Various low fire systems having sintering temperature ≤1300°C like nickel-niobates, bismuth-niobates, bismuth-zinc-niobates, lithium-niobates and lithium-tantalates have been reported. However, the information on these useful materials is sprinkled. The main purpose of this review is to bring together the data on the low fire M-phase lithium based dielectric ceramics with remarkable dielectric properties. Sintering temperature of all the M-phase Li based solid solution has been reduced from 1100°C approximately to about (9000-850°C) with the help of sintering aids. It should be of great help to researchers and technologists across the globe.

Coexistence issues for a 2.4 GHz wireless audio streaming in presence of bluetooth paging and WLAN

Abstract. Nowadays, customers expect to integrate their mobile electronic devices (smartphones and laptops) in a vehicle to form a wireless network. Typically, IEEE 802.11 is used to provide a high-speed wireless local area network (WLAN) and Bluetooth is used for cable replacement applications in a wireless personal area network (PAN). In addition, Daimler uses KLEER as third wireless technology in the unlicensed (UL) 2.4 GHz-ISM-band to transmit full CD-quality digital audio. As Bluetooth, IEEE 802.11 and KLEER are operating in the same frequency band, it has to be ensured that all three technologies can be used simultaneously without interference. In this paper, we focus on the impact of Bluetooth and IEEE 802.11 as interferer in presence of a KLEER audio transmission.

A Modified Technique for Reliable Image Encryption Method using Merkle-Hellman Cryptosystem and Rsa Algorithm

The great advances in digital data communication have led to high desire for a secured and reliable transmission. Advances in satellite communication like packet radio technology and the development of high speed LAN's have created demand for secured applications. Security measures are needed to protect data during transmission. Previous work has characterized reliable cryptosystem for applications like interactive communication, multimedia and data transfer. In this paper, a modified technique for reliable image encryption method using Merkle-Hellman cryptosystem and RSA algorithm is being proposed. By performing block rotation based upon the certain angles achieves better diffusion, which further enhances the security of cipher.

AN OPTIMIZED LOW POWER PIPELINE ANALOG-TO-DIGITAL CONVERTER FOR HIGH-SPEED WLAN APPLICATION

This paper presents the design and implementation of a 11-bit 160 MSPS analog-to-digital converter (ADC) for next generation super high-speed wireless local area network (WLAN) application. The ADC core consists of one front sample and hold stage and four cascades of 2.5 bit pipeline stages with opamp sharing between successive stages. To achieve low power dissipation at 1.2 V supply, a single stage symmetrical amplifier with double transimpedance gain-boosting amplifier is proposed. High speed on-chip reference buffer with replica source follower is also included for linearity performance. The ADC was fabricated in a standard 130-nm CMOS process and an occupied silicon area of 0.95 mm × 1.15 mm. Performance of 73 dB spurious-free-dynamic-range is measured at 160 MS/s with 1 Vpp input signal. The power dissipation of the analog core chip is only 50 mW from a 1.2 V supply.

Network Agent Based on VISA Framework for Instruments

With the rapid development of computer networks,more and more measurements need to relay on the network.But there are only a small amount of instruments with network interface.To access the network,we design a network agent for the instruments with different interfaces. We connect the host with the instrument through the network agent.The agent communicates with the host by using HiSLIP(High-Speed LAN Instrument Protocol ).The client soft front panel controls the instrument based on the VISA(Virtual Instrument Software Architecture) and HiSLIP.We use the Labwindow/CVI to design the soft panel.We can use the soft front panel to manipulate the instrument by the agent quickly and easily.

Network Agent Based on VISA Framework for Instruments

With the rapid development of computer networks,more and more measurements need to relay on the network.But there are only a small amount of instruments with network interface.To access the network,we design a network agent for the instruments with different interfaces. We connect the host with the instrument through the network agent.The agent communicates with the host by using HiSLIP(High-Speed LAN Instrument Protocol ).The client soft front panel controls the instrument based on the VISA(Virtual Instrument Software Architecture) and HiSLIP.We use the Labwindow/CVI to design the soft panel.We can use the soft front panel to manipulate the instrument by the agent quickly and easily.

Performance Measurement of TCP and UDP Using Different Queuing Algorithm in High Speed Local Area Network

In the current high speed networks, it is increasingly important to have mechanisms that keep throughput high but average queue sizes low. The queue management algorithm, which is applied to a router, plays an important role in providing Quality of Service (QoS). This paper present a Simulation-based performance Evaluation of two well known transport layer protocol TCP and UDP using two popular queue management methods; Random Early Detection (RED) and Drop Tail, in terms of throughput, queuing delay, packet drop rate and bandwidth utilization. In this paper we study the effect of buffer behavior on each one of these QoS measurements. TCP, UDP and shared topology scenarios are simulated by considering varying number of client case topologies and also the effect of performance in TCP and UDP with increasing the number of client. This simulation report is useful for implementing the queue management algorithm in router based on the traffic type and bandwidth. Index Terms—TCP, UDP, drop tail, RED queue, bandwidth delay product, throughput and end-to-end delay.

Fourier-Domain Modal Delay Measurements for Multimode Fibers Optimized for the 850-nm Band in a Local Area Network

We present transmission- and reflection-type measurement methods for the differential mode delay (DMD) of a multimode optical fiber (MMF) optimized for high-speed local area networks (LANs) for the 850-nm band. Compared with a previously reported transmission-type measurement method for the 1550-nm wavelength band, we demonstrate here high-resolution DMD measurement methods for MMFs in the 850-nm band. As the method is based on a Fourier-domain intermodal interference technique, the measurement sensitivity is ∼60-dB, and it requires a fiber only a few meters in length. The shorter wavelength also allows a threefold improvement in the measurement resolution. The reflection-type measurement technique is a more practical than the transmission-type measurement technique for the field testing of short MMFs already installed in networks. We believe that this method will be a practical tool not only for field testing of short-length MMFs already installed in networks but also for the development of new plastic optical fibers (POFs).

Dynamic Coloring of Graphs

Dynamics is an inherent feature of many real life systems so it is natural to define and investigate the properties of models that reflect their dynamic nature. Dynamic graph colorings can be naturally applied in system modeling, e.g. for scheduling threads of parallel programs, time sharing in wireless networks, session scheduling in high-speed LAN's, channel assignment in WDM optical networks as well as traffic scheduling. In the dynamic setting of the problem, a graph we color is not given in advance and new vertices together with adjacent edges are revealed one after another at algorithm's input during the coloring process. Moreover, independently of the algorithm, some vertices may lose their colors and the algorithm may be asked to color them again. We formally define a dynamic graph coloring problem, the dynamic chromatic number and prove various bounds on its value. We also analyze the effectiveness of the dynamic coloring algorithm Dynamic-Fit for selected classes of graphs. In particular, we deal with trees, products of graphs and classes of graphs for which Dynamic-Fit is competitive. Motivated by applications, we state the problem of dynamic coloring with discoloring constraints for which the performance of the dynamic algorithm Time-Fit is analyzed and give a characterization of graphs k-critical for Time-Fit. Since for any fixed k > 0 the number of such graphs is finite, it is possible to decide in polynomial time whether Time-Fit will always color a given graph with at most k colors.

Wideband E-Shaped Microstrip Antenna for Wireless Sensor Networks

Problem statement: Wireless Sensor Networks (WSN) is currently receiving significant attention due to their unlimited potential. It is still very early in the lifetime of such systems and many research challenges exist, out of which one of the challenges is sensor processing and fusion under limited capacities, the most important component in sensor is its TX/RX antenna. Approach: For high-speed wireless local area networks and other wireless communication systems covering the 5.33-5.71 GHz frequency band. In this frequency band microstrip antennas have attracted with its low-profile in nature. Microstrip antenna was proposed to meet the challenges, which combines the advantages of compactness with the low cost and low profile of a patch antenna. Results: The key parameters governing the antenna optimization have been determined with the help of High Frequency Simulation Software (HFSS). As a consequence, 5.5GHz microstrip antenna with size 22×16×3.2 mm had been realized on duroid with 2.2. Conclusion: This combination of performance metrics is highly desirable for autonomous distributed sensor network applications where a small sensor node volume and excellent power efficiency are required.

Study of Access Methods in High-speed Photonic LANs (Para-Wave NET)

Study of Access Methods in High-speed Photonic LANs (Para-Wave NET)

Transmitters of Array-type LDs using Side-mode Injection Locking for High-speed LAN

This paper describes a study of transmitters of array-type Fabry-Perot laser diodes (FP-LDs) using side-mode injection locking. The transmitters are assumed to use in the previously proposed high-speed local area network (LAN), Para-Wave NET. Parallel optical transmission with a fiber ribbon and wavelength routing is used in the network. Array-type LDs must be simultaneously injection locked and then switched to another wavelength. The simultaneous injection locking and the wavelength switching have been investigated both experimentally and theoretically. We estimate acceptable cavity length deviation of LDs in an array by considering locking ranges. It is desirable to emit no power from an LD during switching or in the case of no-sending packets. However, it emits unnecessary power in the case of free run- ning states. Two possible methods to suppress free running states are investigated.

Synthesis of Forsterite with High Q and Near Zero TCffor Microwave/Millimeterwave Dielectrics

With the advent of ubiquitous age, the high quality dielectric materials have been required for the wireless communications available to the millimeter-wave as well as microwave frequencies. The utilizable region for the frequency has been expanding to the millimeter-wave region because of the shortage of radio frequency (RF) resources. These high frequencies would be expected for ultra high speed LAN, ETS and car anti-collision system on the intelligent transport system (ITS) and so on. Silicates are good candidates for microwave/millimeterwave dielectrics, because of their low dielectric constant e r and high quality factor (High Q). Forsterite (Mg₂SiO₄) is one of the silicates with low e r of 6.8 and Qㆍf of 240000 ㎓. In this paper, we reviewed following three categories for synthesis of forsterite: (1) Synthesis of high Qㆍforsterite (2) Adjust the temperature coefficient of resonant frequency TC f (3) Diffusion of SiO₄- and Mg-ions on the formation of forsterite

Crosstalk Control of High Speed LAN Connectors

NEXT (Near End loss) and FEXT (Far End loss) of a high speed LAN connector are analyzed using a simple coupled line model and examined experimentally. Crosstalk Chart is also proposed, by which, the NEXT and FEXT can be easily read off from the mutual inductance and unbalanced capacitance between pair of lines. This approach is effective for Cat.5e [1] connectors. However, for Cat.6 [2], of which transmission bandwidth is widen to 250 MHz, some additional adjustments of path pattern on the jack and terminals PCB are required. In order to assist such the adjustments, a new simple measurement technique to grasp the complex crosstalk characteristics is proposed. Two examples are introduced. One is a conventional telephone rosette, which is enhanced to be co-usable for a Cat.5e LAN connector, where only its original circuit board is reengineered. Another is a Cat.6 connector of which PCB is modified from a conventional Cat.5e connector.

Current problems in parallelization of the computation algorithms and organization of parallel computations

The last decade witnessed an intensive development of the network technologies which enabled a multifold increase in the computer throughput. The matter primarily concerns design of the supercomputers, the most powerful modern computer systems based on the concept of parallel processing of massive data. For example, the supercomputers combining the commercial processors and the facilities of the high-speed LAN’s have become widespread. Another, cheaper path to using the network technologies lies in organizing the so-called distributed computational environments. The gist of this approach lies in uniting the already existing LAN computers, this union being regarded as a single parallel computer. Yet, as compared with the supercomputer based on the commercial processors, this computer system has a lower reliability on account of different membership of the network computer nodes, higher structural nonuniformity on account of different architectures of the nodes, and other distinctions. At that, the problems of establishing efficient means of data exchange between the individual nodes and optimizing the topological structure of the network come to the forefront just as it is the case with the supercomputers. As was already mentioned, the parallel data processing is the characteristic feature of the modern high-speed computer systems. That is why the dedicated software and its proper databases for parallel operation become topical. The supercomputers and distributed computer systems enable one to settle many complicated— and previously intractable or unsolvable—applied problems such as the control of the dynamic systems which in practice have huge dimensions and are labor-intensive. Solution of such problems by the existing computational facilities requires special algorithms taking into account the characteristics of this hardware and enabling parallelization of computations. All of the aforementioned problems such as the outlooks for design of the supercomputers, features of the distributed computer environments, methods of organization of the parallel databases, and optimization of the local-network architecture are considered to a certain extent in the papers published in this issue of Automation and Remote Control . Diverse parallel computation-based algorithms for different fields of mathematics such as discrete and stochastic optimization, mathematical programming with search of the global extremum, statistical modeling of the gas dynamics, direct and inverse problems of the mathematical physics, and so on were proposed. Consideration was also given to numerous applied problems whose solution makes use of the parallel computation technology. We expect that publication under one cover of the papers of renowned researchers that are devoted to a single subject will attract interest of the experts in parallel computations. Although some papers by themselves are beyond the scope of the subject-matter of this issue, together they assume a new sense and, in our opinion, will be of use to the readership of Avtomatika i telemekhanika. I.I. Eremin, A.I. Kibzun

Computation on the Optimal Control of Networked Control Systems with Multiple Switching Modes Over High Speed Local Area Networks

The optimal control problem for the networked control system with multiple switching modes over high speed local area networks is addressed, where an initial state is a parametric vector. Because in the general case, the time delay is much less than the sampling period and the possibility of the packets collision is much lower, it can be assumed that the influence of the time delay and the packets loss on the optimal controller design can be ignored. On the basis of the assumption, the networked control systems with multiple switching modes are modeled as a hybrid system. Moreover, based on the Bellman type inequality for the hybrid systems, a dynamic program to solve the optimal control with a parameter vector is proposed, in every step of the technique, the feasible region is divided into evenly distributed grid points, and then, the optimal control law is transformed into maximizing the lower bound of the cost to go function in grid points. Finally, an experiment setup of the networked control system with multiple switching modes is constructed and a simulation example is given to illustrate the optimal control computation results.